• 
• 

Three Part Question

In [otherwise healthy term (>37 weeks) newborns less than 14 days old born in NZ] can [transcutaneous bilirubin monitoring be used to detect jaundice below treatment line] [reducing the need for serum bilirubin measurements]?

Clinical Scenario

A 6 day old baby was seen in CEC with mild increase in WOB. The baby was saturating well and was feeding normally so parental education was given and they were advised to go home and return if things change. However, before discharge the parents mentioned they were worried about the yellow tinge to babys skin. The history revealed no risk factors for pathological jaundice, however, before discharge a serum bilirubin level (SBR) was done to ensure normal bilirubin levels and put the parents mind at ease. The results showed serum bilirubin was well below the treatment line (122umol/L). Was it necessary to bleed this baby or would a transcutaneous bilirubin measurement have been an effective method to rule out significant hyperbilirubinemia?

Search Strategy

SCOPUS search using the terms 'neonatal jaundice' AND 'transcutaneous bilirubin measurement'
The search was restricted to papers published between 2018-2022 due to the improving quality of transcutaneous bilirubin measurement devices.

Search Outcome

79 papers were found, of which 7 were deemed to be relevant.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Hulzebos, C.V., Vitek, L., Coda Zabetta, C.D. et al. 19 March 2021	18 studies	Literature Review		TcB values provide a reasonable estimate of TSB levels in healthy newborns with correlation coefficients ranging from 0.70 to 0.97	With a literature review, there is no set method to ensure all the literature on a topic was considered, therefore, the chances of the review being biased increases. Methods of research aren't discussed. 6 out of the 18 papers were published in 2015 or before. Therefore, the use of older transcutaneous bilirubin monitors may skew the results.
				instruments may overestimate TSB at low values and underestimate TSB at high values.
Charles I. Okwundu, Shiv Sajan Saini, 2021	54 studies assessing the accuracy of TcB	Literature review		TcB can be a suitable alternative measure TB levels < 15 mg/dL (257 mmol/L) in newborns.	Many of the included studies did not report blinding of the observers, although this is unlikely to make much difference due to the objective nature of the results. Different TcS devices used in each study. These were not reported or discussed. Relevant literature from 1966 to January 1, 2020. There is evidence that newer devices are more accurate.
				Black newborn was considered to impede TcB accuracy in older devices. This is addressed by newer devices.
				Prior exposure to phototherapy impacts skin color and impedes results.
Carolyn Nassuna, Abdallah Yaser, Charles Karamagi, and Jamir Mugalu Uganda	235 well neonates 24 to 72 hours of age due for discharge	Cross-sectional study		Transcutaneous bilirubi- nometry identifies majority of neonates with SHB	Low resource setting is a different demographic than Christchurch hospital. Babies are all from Uganda and therefore have dark skin tone making this study not generalisable to the NZ population. Majority of our participants were born by cesarean section.
Adriaansen, M., Williams, S., & van den Boom, J. 2022 New Zealand	184 healthy neonates above 36 weeks gestation between 24 hours and 13 days old weighing <2500g at birth.	Prospective study Using Scanmedics Bilicare AND Philips Bilichek - preferred		Transcutaneous bilirubin meters can be used for neonatal bilirubin measurements with appropriate treatment thresholds and clinical pathways.	Limited by the number of neonates involved, particularly the number of light skin-tone and dark skin-tone neonates (63% were medium-skin tone based on Fitzpatrick Skin Tone Scale). Accuracy of the meters may be further reduced when introducing multiple users to take transcutaneous bilirubin readings.
				Transcutaneous bilirubin meters can reduce the number of total serum bilirubin tests required with cost savings to health care providers.
				Cut off of 200umol/L ensured 0% of neonates were missed compared to 1.3% with the Bilichek and 3.3% with the Bilicare
				Bilichek had a negative predictive value (NPV) 98%, Bilicare had an NPV of 96%
Chua, B.-S., Song, L.-H., Chang, C.-T., Lim, X.-J. and Nachiappan, J. 2021 Malaysia	1842 babies	Prospective, observational study		No babies with severe jaundice were missed by the transcutaneous bilirubin screening	Study conducted in Malaysia - not generalisable to NZ population. The study does not report the baseline demographics of the participants. This is likely due to the study being in conducted opportunistically during lockdown when the health system is already very stretched
				DT transcutaneous bilirubin screening method for neona- tal jaundice is a non-invasive, painless, rapid, cost-effective and practical solution
Costa-Posada, U., Concheiro-Guisán, A., Táboas- Ledo, M.F. et al. 2022 Japan	788 term neonates in the first 4 days of life	retrospective chart review Uses JM-105 Bilirubinometer		To evaluate neonatal jaundice accurately, it is desirable to measure TSB by blood sampling before discharge from obstetrics	Japanese cohort - loses generalisability to NZ
				TcB is useful as a noninvasive jaundice screening test but is not a substitute for TSB.
Shah MH, Ariff S, Ali SR, et al 2019 Pakistan	3209 non-high risk >37 weeks	retrospective and prospective cohort. Dragger JM-105 TcBR metres were used	Reduction in the number of blood bilirubin samples for TSBR.	TcBR testing used in conjunction with our proposed nomogram significantly reduces the need for serum bilirubin sampling.	The study was not designed to assess the accuracy of TcBR readings as this has already been well established in Pakistan. - Saeed T. Validity of Transcutaneous Bilirubinometer in Neonates as compared to Laboratory serum Bilirubin Estimation. Journal of Rawalpindi Medical College 2013;17:81–3. - Nahar N, Mannan MA, Dey AC, et al. Comparison of Serum Bilirubin with Transcutaneous Bilirubinometry in Late Preterm and Term Newborn. Mymensingh Med J 2017;26:621–7.
			Reduction in the cost of blood bilirubin sampling.	It is a safe, easy to use, cost-effective method and also prevents unnecessary painful pricks.

Comment(s)

Many of the studies had a study population very similar to the population in question; otherwise well term (>37 weeks)infants with no risk factors for pathological jaundice. However, one major weakness is the lack of generalisability to the New Zealand population in all but one study. Many of these studies were completed in Asian or higher melanin populations. It has been proven in the past that skin colour has an impact on the accuracy, however, there is some evidence that newer devices negate this. Therefore, it was great to find a study looking at the efficacy in the New Zealand neonatal population as there are no previous studies validating transcutaneous bilirubin devices with Maori or Polynesian populations. Ease of use and cost analysis was also briefly assessed (NZ) and were shown to reduce the number of total serum bilirubin tests required with cost savings to health care providers. This is backed up by the study by Shah MH, Ariff S, Ali SR, et al which showed significantly reduces the need for serum bilirubin sampling and proved it to be a cost-effective method and also prevents unnecessary painful pricks. One important thing to note is the potential discrepancy between brands of TcS devices. Past studies have shown TcS monitoring to be unreliable, however, newer devices seem to give much better results. It is interesting to note that the WOMEN’S HEALTH SERVICE at Christchurch Women’s Hospital guidelines recommend JM-105. This monitor was assessed in the studies which concluded it was a suitable screening tool for otherwise healthy term infants, however, not a replacement for serum bilirubin measurements at higher levels when interventions are being considered. Having guidelines for further investigation is essential. At higher and lower bilirubin concentrations, TcS monitors seem to lose accuracy. UpToDate guidelines state that measurements should be confirmed with TSB measurements when therapeutic interventions are being considered, f TcB is within 51 micromol/L of the phototherapy threshold, if TcB is >257 micromol/L, if the device reports an "error" message, or if there is any question regarding the validity of the TcB measurement.

Clinical Bottom Line

If baby is otherwise well with no risk factors for pathological jaundice, transcutaneous bilirubin monitors can be used as a cost effective, minimally invasive test to assess hyperbilirubinemia and determine whether further evaluation with serum bilirubin is necessary. It is important to note that it becomes less accurate at higher levels of bilirubin, therefore, it is important to use tailored guidelines alongside TcS monitors to indicate when further investigation is required.

References

1. Hulzebos, C.V., Vitek, L., Coda Zabetta, C.D. et al. Screening methods for neonatal hyperbilirubinemia: benefits, limitations, requirements, and novel developments Pediatr Res 2021; 272–276:
2. Okwundua, C.I, and Sainib, S.S. Noninvasive methods for bilirubin measurements in newborns: A report Seminars in Perinatolog 2021
3. Carolyn Nassuna, Abdallah Yaser, Charles Karamagi, and Jamir Mugalu Significant hyperbilirubinemia among well neonates due for discharge at Kawempe-Mulago Hospital, prevalence, factors associated, and accuracy of transcutaneous bilirubinometry for screening African Health Sciences June 2022; 526–534
4. Adriaansen, M., Williams, S., & van den Boom, J. Evaluation of two transcutaneous bilirubin devices for the assessment of neonatal jaundice in a diverse New Zealand population New Zealand Journal of Medical Laboratory Science 2020
5. Chua, B.-S., Song, L.-H., Chang, C.-T., Lim, X.-J. and Nachiappan, J. Drive-through transcutaneous bilirubin screening for neonatal jaundice: A safe and efficient system during the COVID-19 pandemic Journal of Paediatrics and Child Health 2021; 12-14
6. Costa-Posada, U., Concheiro-Guisán, A., Táboas- Ledo, M.F. et al. Accuracy of transcutaneous bilirubin level measured by a JM-105 bilirubinometer J Perinatol 2022; 226–231
7. Shah MH, Ariff S, Ali SR, et al Quality improvement initiative using transcutaneous bilirubin nomogram to decrease serum bilirubin sampling in low-risk babies BMJ Paediatrics 2019